Senior Tory and former Defense Secretary Liam Fox has urged Prime Minister David Cameron to end the “pretense of EU reform” and allow cabinet members to campaign for leaving the EU without having to resign.

Writing in the Sunday Times, Fox said: “The fact that a British prime minister has been in effect forced to take the political begging bowl around European capitals in order to make the laws he believes are necessary for Britain is the best possible demonstration of the problem.”

Fox’s comments come after Cameron met with EU leaders in Brussels on Thursday to discuss restructuring the UK’s relationship with the 28-member bloc. Cameron is seeking to find a political agreement before holding a referendum on EU membership before the end of 2017.

Fox said cabinet members should be able “to express what’s effectively a matter of conscience” without having to resign.

“I think that the more that we’re able to give freedom to our colleagues and treat one another’s views with respect, the easier I think it will be for us to come together after that referendum to continue to govern the country.”

Liam Fox has tonight declared Britain should leave the EU in the Sunday Times. Most senior figure who has served Cameron's govt to opt out

Steve Baker, MP for Wycombe and head of the Eurosceptic Conservatives for Britain campaign, also indicated on Sunday that several cabinet members want Britain to leave the EU.

“It’s inevitable that some members of the cabinet would have to resign if they’re browbeaten into supporting a deal that is honestly this flimsy,” Baker told Sky News.

Other top Tories, however, sided with the PM. Former Prime Minister John Major, a close ally of Cameron, told the BBC on Sunday the UK would be less safe, less prosperous and less influential outside of the EU, warning that a vote to leave would be irreversible.

“It’s not politically credible to go back and say ‘we’ve reconsidered, let’s have another referendum.’ If we vote out then we are out and we will have to get on with it and face the consequences.”

Pressing for party unity, he said: “This is bigger than the Conservative Party. People deserve to hear a clear-cut argument, not an internecine piece of party strife.

“It’s a classic European situation,” said Major.

“On both sides they are setting out positions and they will meet and a compromise will be reached, and the compromise won’t just deal with trivial issues.”

On Friday, Cameron announced the UK would “fundamentally change” its relationship with the EU in the coming year. However, Cameron’s demands have been criticized by Euroskeptics as trivial. They worry the renegotiations will not curb migration to the UK from other parts of Europe.